Domestic appliance



Aang. 6, 1946.

K. CLARK DOMESTIC APPLIANCE Filed Oct. 29, 1940 2 Sheets-Shawl.v 1

W W a S n m A K. CLARK DOMESTIC APPLIANCE ma@ s, 194s.

Filed Oct. 29, 1940 2 Sheets-Sheet 2 ATTORNEY` Patented Aug. 6, 1946 DOMESTIC APPLIANCE Kendall Clark, Oakwood, Ohio, assigner to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application October 29, 1940, Serial No. 363,321

Claims. l

This invention relates to domestic appliances and more particularly to a clothes washing machine of the centrifugal type.

An object of this invention is to provide a centrifugal machine which automatically counter-balances the variable load produced by unequal distribution of clothes Within the centrifugal basket.

Another object of this invention is to provide a centrifugal machine with an automatic balancing device which is eiTectiVe at all speeds of rotation.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a vertical cross sectional view of the machine;

Fig. 2 is a horizontal cross sectional View taken along the line 2-2 of Fig. 1;

Fig. 3 is an elevation of a portion of a machine; and

Figs. 4 and 5 are plan views of slight modifications.

In a machine wherein clothes are subjected to centrifugal action to remove water from them, an olf-balance distribution of the clothes creates a Whipping action during rotation, which is objectionable and even dangerous. Such olfbalance distribution of clothes is diihcult to counteract because it varies in magnitude and location in the centrifugal basket.

I have invented a washing machine which utilizes the centrifugal principle to Wring the clothes, but I have provided eiiicient means to counteract the effect of off-balance distribution of clothes. In addition I have provided washing means within the centrifugal basket which tends to distribute the clothes more or less evenly around the basket. Thus I have provided a washing machine in which liability of uneven distribution of clothes is reduced and in which such uneven distribution as may occur is efficiently counteracted.

In addition, I have provided a counterbalancing device which is effective at all speeds of rotation of the basket. My counterbalancing device automatically compensates for the increased radial acceleration due to any increased speed, which the unbalanced load may have.

To accomplish this, my washing machine includes a rotatable basket driven by mechanism contained within the casing Il. The basket and casing are p-ivotally and resiliently supported by ward stroke.

w shaft I4, preferably at about 350 cycles per minute and with an amplitude of about 1% inches. The agitator is provided with a flexible collar I5, made of rubber or the like at its lower periphery to increase the agitationg power on the down- The oscillations are sufficiently rapid to produce a toroidal action of the water and the clothes within the basket, tending to produce a doughnut-like ring while the basket is stationary. This distributes the clothes somewhat evenly before centrifugal action begins, but

some unbalance remains, which tends to deflect the basket when it is rapidly rotated.

A counterbalancing means, eective during rotation, is secured to the basket which automatically tends to counterbalance any unequal eccentric load produced by such uneven distribution of clothes. The counterbalancing means comprises a plurality of pendulum weights I5 pivotally secured to the ring I'I by pins I3. The

ring Il, is, in turn, secured to the basket I (I through the medium of rotatable shaft 24, which carries the basket and is driven by the motor 20 in the casing II. The pendulum weights I6 are so proportioned that their natural frequency of oscillation and vibration, under the correspondsystem, which comprises the unbalanced load,

the basket and the driving mechanism. The function of the weights, in acting as tuned vibration absorbers is to reduce vibration by bringing the center of gravity 0f the entire system (includ- -ing the vibration absorbers and the unbalanced load) to coincide with the axis of rotation. The center of gravity of an unbalanced system (without the vibration absorbers) does not coincide with the axis of rotation and considerable vibration is caused at spinning speeds. The weights are an effective counterbalance because they eliminate the unbalanced vibration by bringing the center of gravity of the entire system into coincidence with the axis ofspin. The reason why this tuned vibration absorber countercounterbalances the unbalanced load. Once theY weights have arranged themselves to counterbalance any particular off-balance load, they cease to move about their fulcrums and remain with their composite center of gravity diametrically opposite the center of gravity of the offbalance load. Under these conditions, unbalanced Vibrations are eliminated from the machine. I have indicated the unbalanced load to be at right angles to the pendulums I 6a and IIb. However, if the load should not be at right angles to any pair of pendulums, the vectors of force of the various pairs of pendulums automatically are of such a size as to counterbalance the load regardless of its meridian position in the basket.

To achieve pendulums of correct proportions to vibrate at a frequency coincident with the frequency of rotation:

A. Determinethe center of gravity of a pendulum:

B. Find the natural period of vibration of the pendulum while swinging as a gravitational pendulum; and

C. Place the center of gravity and the pendulum pivot radially inline with the tub spinning axis, the center of gravity of the pendulum being at a radius from the axis such that the radial acceleration on the center of gravity of the pendulum, when the unit is rotated at a frequency equal to the frequency obtained under B above, is equal to the natural acceleration of gravity.

All of the pendulums may be made similar, and may be arranged symmetrically around the axis of the tub, and when so arranged and proportioned, they will act as a tuned vibration absorber or automatic counterbalancer to prevent violent radial displacements or centrifugally caused vibrations of the tub during all speeds of rotation from the starting speed to the ultimate maximum speed of rotation.

The motor reciprocates the shaft I4 and rotates the shaft 24 through the medium of transmission 23. Any motor and transmission may be used to accomplish this. Preferably, the motor reciprocates the shaft I4 and agitator I3 vertically when the motor is rotated in one direction, and rotates the shaft 24, basket I0 and the shaft I4 when the motor is rotated in the opposite direction. Details of construction of the motor and transmission are more fully described in my copending application Serial No. 358,871 led September 28, 1940, for Domestic appliance, to which application reference is made for all details of construction and operation not inconsistent with this disclosure.

The bottom of the casing II preferably is anchored to the main frame 30 of the washing machine by means of a flexible snubber 3|. This snubber aids the counterbalancing action of the pendulums I6. The frame 30 preferably is in the form of a vertical casing having a central partition 32 which forms a trough and also forms a support for the collar I2. When the basket is rotated, the water is discharged through the openings 33 and 34 into the outer cup 35 of the basket II) from whence it is discharged over the lip 36 into the casing 30 where it falls into the trough 32. The water may then flow through the flexible hose 31 to a pump 38 in the bottom of casing II, driven by motor 20. The water is discharged by the pump 38 through the flexible hose 39 into any convenient drainage receptacle.

During operation, the clothes are placed in the basket II), together with the proper amount of detergent and water. Thereafter, the motor controller, in the manner disclosed in my copending application Serial No. 358,871, energizes the motor to rotate in a direction to produce vertical reciprocation of the agitator I3. This produces toroidal action, as indicated by the arrows 40, in the clothes and water. After a suilicient length of time, the motor 20 is reversed to rotate the basket I0. This causes the water to be discharged through the openings 3 3 and 34 into the outer tub 35 and from thence over the lip 36, as previously described. Thereafter, a sufficient number of rinse waters may be introduced into the tub I0, with subsequent agitation during and rotation after, each rinsing, all as described in my said copending application. During all of these operations, the clothes may be slightly unevenly distributed. The pendulum Weights I6 automatically counterbalance the unbalanced load produced by such uneven distribution.

The weights I6 should be of sufficient mass to counter-balance the maximum expected unbalanced load. In a domestic washing machine of about 20 inches maximum diameter of tub, a maximum unbalanced load equivalent to three pounds along the circumference may be expected. The weights I6 should be of suicient mass that the moment of their common center of gravity at maximum pendulum displacement is equal to, or greater than, that of the maximum unbalanced load.

Fig. 4 shows a slightly modied form of counterbalancing weight. Several weights of the type shown in Fig. 4 are used exactly as shown in Fig. 2, but the connection of the weightto the basket is slightly modified. The weight IGc is pivoted or flexibly supported on the pin I8c with an interposed sleeve I8d made of rubber or similar material. This sleeve I8d supports the weight I6c oscillatably, and the internal friction of the rubber may improve the operation of the unit by contributing a slight amount of damping of the vibrating system. The pin IBc is carried by a ring similar to ring I1 of Figs. l, 2 and 3.

In Fig. 5 a weight IScZ may be attached to the basket by means of a light spring |86 which is secured to a hub similar to hub I'I of Figs. 1, 2 and 3. The spring I8e is iiexible to the extent that it does not appreciably affect the vibrating period of the weight under centrifugal forces. Several weights IEd of the type shown in Fig. 5 are used in the same manner as illustrated with respect to weights I6 of Figs. 1, 2 and 3.

In all of the modifications oscillation limiting stops or pins Ila are provided to limit the motion of the counter-weights during acceleration and deceleration of the basket. The pins I'Ia may be supported from the upper flange of the ring I1.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope'of the claims which follow.

What is claimed is as follows:

1. A centrifugal machine comprising a rotatable basket, a support for said basket permitting lateral movement thereof when an unbalanced load is in said basket, power means connected to said basket to accelerate said basket through a large speed range through gradually increasing speeds to e, high speed, means for counterbalancing variable unbalanced loads in said basket throughout said speed range of said basket, thereby to prevent lateral movement of said basket due to an unbalanced load, said counterbalancing means comprising a set 0f independent weigh'ts each supported to swing in a plane perpendicular to the axis of rotation of said basket about circumferentially spaced pivots xed relative to said basket, said weights being sufficiently heavy with respect to said unbalanced loads and said pivots being so located that said weights arrange themselves with their common center of gravity equal and opposite to the center of gravity of said unbalanced loads to cause said weights tol exert an automatic counterbalancing reaction to a variable eccentric load in said basket.

2. A centrifugal machine comprising a basket mounted to rotate about a vertical axis, a support for said basket permitting horizontal movement thereof away from said axis when an unbalanced load is in said basket, power means connected to said basket to accelerate said basket through a large speed range through gradually increasing speeds to a high speed, means for counterbalancing variable unbalanced loads in said basket throughout said speed range of said basket, thereby to prevent lateral movement of said basket due to an unbalanced load, said counterbalancing means comprising a set of independent weights each supported to swing in a plane perpendicular to the axis of rotation of said basket about circumferentially spaced pivots iixed relative to said basket, said weights being symmetrically arranged about said axis and being suiiiciently heavy with respect to said unbalanced loads and s'aid pivots being so located that said weights arrange themselves with their common center of gravity equal and opposite to the center of gravity of said unbalanced loads to cause said weights to exert an automatic counterbalancing reaction to a variable eccentric load in said basket.

3. A centrifugal machine comprising a basket rotatable about a vertical axis, a support for said basket beneath said basket permitting lateral movement thereof when an unbalanced load is in said basket, power means below said support and connected to said basket to accelerate said basket through a large speed range through gradually increasing speeds to a high speed, means for counterbalancing Variable unbalanced loads in said basket throughout said speed range of said basket, thereby to prevent lateral movement of said basket due to an unbalanced load, said counterbalancing means comprising a set of independent weights each supported to swing in a plane perpendicular to the axis of rotation of said basket about circumferentially spaced pivots fixed relative to said basket, said weights being symmetrically arranged about the axis of rotation of said basket and being suiiciently heavy with respect to said unbalanced loads and said pivots being so located that said weights arrange themselves with their common center of gravity equal and opposite to the center of gravity of said unbalanced loads to cause said weights to exert an automatic counterbalancing reaction to a variable eccentric load in said basket.

4. A centrifugal machine comprising a, rotatable basket, a support for said basket permitting lateral movement thereof when an unbalanced load is in said basket, power means connected to said basket to accelerate said basket through a large speed range from a stationary condition to a high speed, means for counterbalancing variable unbalanced loads in said basket throughout the entire speed range of said basket, thereby to prevent substantial lateral movement of said basket due to an unbalanced load, said counterbalancing means lcomprising a set of independent weights each' supported to swing in a plane perpendicular to the axis of rotation of said basket about circumferentially spaced pivots fixed relative to saidfbasket, said weights being suiciently heavy with respect to said unbalanced loads and said pivots being symmetrically arranged about the axis of the basket and being so located that said weights arrange themselves with their common center of gravity equal and opposite to the center of gravity of said unbalanced loads at higher speeds to cause said weights to exert an automatic counterbalance reaction to a variable eccentric load in said basket, and means effective during early acceleration of said basket for maintaining said weights symmetrical to the axis of the basket.

5. A centrifugal machine comprising a rotatable basket, a support for said basket permitting lateral movement thereof when an unbalanced load is in said basket, power means connected to said basket to accelerate said basket through a large speed range from a stationary condition toa high speed, means for counterbalancing variable unbalanced loads in said basket throughout the entire speed range of said basket, thereby to prevent substantial lateral movement of said basket due to an unbalanced load, said counterbalancing means comprising a set of independent weights each' supported to swing in a plane perpendicular to the axis of rotation of said basket about circumferentially spaced pivots xed relative to said basket, said weights beingsuiiciently heavy with respect to said unbalanced loads and said pivots being symmetrically arranged about the axis of the basket and being so located with .said weights arrange themselves with their common center of gravity equal and opposite to the center of gravity of said unbalanced loads at higher speeds to cause said Weights to exert an automatic counterbalance reaction to a variable eccentric load in said basket, and stop pins arranged symmetrically with respect to the axis of the basket against which said weights impinge during the early acceleration thereby to maintain said weights symmetrical during said early acceleration.

KENDALL CLARK. y 

